1. Field of the Invention
The present invention relates to an ink-jet printing apparatus and an ink-jet printing method, particularly suitable for textile printing, which employs textile or cloth as a printing medium, and ejects an ink to the textile by means of an ink-jet head as a printing head.
2. Description of the Related Art
In the recent years, there have been known ink-jet printing apparatuses performing textile printing employing an ink-jet type printing system. Different from the conventional screen textile printing, this type of textile printing apparatus achieves advantages because an original plate is not required, a freedom of image to be printed is high, and overall cost for textile printing can be low.
Japanese Patent Application Laid-Open No. 212851/1993 discloses one embodiment of a textile printing apparatus employing an ink-jet system. As can be clear from FIG. 2 of the above-identified publication, this type of textile printing apparatus performs printing by ejecting an ink from an ink-jet head to a textile as a printing medium, transported in a vertical direction. In a printing portion performing ink ejection, a printing unit having the ink-jet head and a transporting mechanism including a metallic endless belt, i.e., a transporting belt, are arranged in opposition across the textile.
The textile is adhered on the surface of the transporting belt to maintain flatness. Then, by intermittently driving the transporting belt, the textile is transported for a predetermined width.
The textile is printed per one printing width by the known serial printing system, and thereafter is applied an appropriate tension by a textile take-up roller arranged at the most downstream side of the transporting path. Then, at an end portion of the transporting belt, the textile is peeled off the transporting belt and taken up on the take-up roller via a textile path.
Next, after printing, immediately after peeling off the transporting belt, a drying process is performed on the textile for the ink in the printing portion of the textile by means of a drying process apparatus. For the drying process apparatus, a system blowing hot air on the printing surface of the textile or a system irradiating an infrared ray on the printing surface of the textile may be selected arbitrarily. Such drying processes are particularly effective when a liquid state printing agent is employed.
On the other hand, a textile printing ink applied to the textile by the ink-jet type textile printing merely adheres on the textile. It is required to fix the coloring agent in the ink, such as dye by making impregnation. It is typical for a rough standard of impregnation amount to be evaluated by the strike through amount (permeation amount of the ink towards the back side of textile printing surface) by observation from the back side as the non-printed surface. In the case of the ink-jet textile printing, in which the application amount of the ink, such as dye, is smaller in comparison with the conventional screen textile printing, an effort is often made to compensate for the shorting of the strike through amount by overlapping printing.
However, when reciprocating overlapping printing is performed by the same printing head in order to increase the strike through amount, productivity is lowered in a manner inversely proportional to the number of times of overlapping printing. As a result, a cost for printed textile is increased.
On the other hand, overlapping printing by a plurality of stages of printing heads, greater than or equal to three stages, increases the cost for a textile printing apparatus in proportion to the number of steps of the printing heads.